Check legality of some of the referenced libraries and icons

[qtrandev]

Check if we need to include any legal copyright notices or attributions to the projects used:

1. Google Maps layers (Map, Satellite, Traffic) used under Leaflet
   https://developers.google.com/maps/documentation/javascript/

Usage of Google.js in
https://github.com/qtrandev/LeafletTransit/blob/master/googlemaps/Google.js
obtained from
https://github.com/shramov/leaflet-plugins/blob/master/layer/tile/Google.js

2. Usage of icons in
   https://github.com/Code-for-Miami/LeafletTransit/tree/gh-pages/icons
   All the transit agency icons should be government property so we should be ok, but please check.
   The trolley icons are private companies making them available for cities so not sure here.
   The Citi bike icon is definitely private, so we need to remove or replace that.

3. Usage of Leaflet - do we need anymore attributions?